


It’s not Saturday

by sorryallonsy



Category: The Umbrella Academy (TV)
Genre: Alpha/Beta/Omega Dynamics, Breeding Kink, Knotting, M/M, Mpreg, Pseudo Incest, Scent Kink, alpha! Diego, heat - Freeform, omega! klaus
Language: English
Status: Completed
Published: 2019-05-06
Updated: 2019-05-06
Packaged: 2020-02-27 03:36:06
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,015
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18730897
Author URL: https://archiveofourown.org/users/sorryallonsy/pseuds/sorryallonsy
Summary: Klaus pauses in the doorway, turning slightly to look at Diego over his shoulder. “Are you gonna come, Alpha?” he asks, giving Diego his most innocent Look. Then, without waiting for an answer, he spins and walks out of the room.





	It’s not Saturday

**Author's Note:**

  * For [xofrnakxo](https://archiveofourown.org/users/xofrnakxo/gifts).



> For Em <3  
> It got away from me a little bit lol, but I hope you enjoy!

They’d been in their new normal lives for about six months now. At the time they’d had so much to figure out, trying to piece together what was different in this world from the world that they used to live in. A lot, apparently. With Ben alive, the Umbrella Academy never had the great falling out. Vanya didn’t write her book, Luther didn’t flatline on a mission or get turned into part gorilla, and Allison… Allison never rumored Patrick into loving her, so she never had Claire. Understandably, the news was incredibly hard to take, so they all decided to move back into the Academy to be there to support Allison, and each other as well. 

Currently, they were all in the living room, listening as Vanya played one of her concertos for them. She had been wary about taking up her violin again after everything that happened with the apocalypse. It was Luther, actually, who had been the first to suggest she go back to her music, stating that this time around they were all there to support her, to support each other. Even Diego admitted that Luther was finally starting to act like a leader for once. 

Klaus looked around the room at his family, his pack. Growing up, they’d been forced into their pack out of necessity over actual family dynamics. They were actively discouraged from forming any actual bonds with one another, only allowed the most basic of connections that even Reginald hadn’t been able to find a way to avoid. 

Klaus took a deep breath in, letting everyone’s scents wash over him. They smelled like home, and safety, and his. His stomach clenched at the thought, and he was suddenly struck by the realization that he hadn’t gone into heat since they’d avoided the apocalypse, and was most definitely due. As if he were thinking it into existence, he felt a light trickle between his butt cheeks, and shifted in his seat to alleviate the discomfort. It would be a little while still until he went into a full blown heat, and there was no reason to interrupt Vanya’s performance for a little wetness.

Beside him, Diego was watching him closely, and Klaus could see his nostrils were flared, his jaw clenched tight. _Interesting._ Klaus stretched, bringing both arms behind his head before settling back into the couch, uncrossing and re-crossing his legs then resting one arm behind Diego. Klaus is watching Diego carefully, so he notices when Diego takes a breath in and doesn’t let it out. _Very interesting indeed._ Klaus turns back towards Vanya after that, but his thoughts were all on the alpha next to him holding his breath.

Vanya’s performance doesn’t go on for long, she didn’t want to tempt her powers too much too soon with a lengthier piece. As she finishes, and the siblings all start clapping for her, Klaus takes his time retrieving his hand from around Diego’s neck. As tempting as it is to run his fingers over Diego’s scent gland on his neck, even he isn’t that daring in a room full of other people, so instead he settles for brushing his fingers through Diego’s hair before jumping up and clapping for Vanya. Grace decides that celebratory cookies are in order, so they all start heading down to the kitchen, except for Diego, who’s still sitting on the couch with a confused look on his face.

Klaus pauses in the doorway, turning slightly to look at Diego over his shoulder. “Are you gonna come, Alpha?” he asks, giving Diego his most innocent Look. Then, without waiting for an answer, he spins and walks out of the room. He manages to get halfway down the stairs to the kitchen before Diego catches up to him. A hand on Klaus’ arm gets him to pause, and he lifts his eyes to look at Diego. 

“Look, I don’t know what game you’re playing at…” 

“A game??” Klaus tilts his head to the side, making sure to display his neck to the alpha. “But Diego, it’s not Saturday.”

A low rumbling growl escaped Diego at that, and he surged forward, caging Klaus in against the wall. He opened his mouth to say something, when Klaus tipped his head further, submitting. Diego froze, then leaned in, pressing his nose against Klaus’ scent gland. 

Klaus always had a soft sweet smell about him. When they were younger, Diego always said he smelled like mom’s cookies, though as he got older and more into drugs, it changed, smelling more artificial, like an old air freshener hanging in a car. Right now he smelled like a strange mix between the two, but there was more to it too. Something sweeter, inviting Diego in. He wanted to taste it, wanted to bite it, to claim it. He wanted…

“Diego?” Allison was climbing up the stairs behind them, probably checking to make sure neither of them left early. “Klaus? What’s going on guys?” 

Diego quickly sprang away from Klaus, though not before Allison saw exactly what he was doing. 

“Were you _scenting_ him?!” 

Rather than acknowledge what Allison was saying, Diego just brushed past her, heading to the kitchen. 

Allison turned her attention then to Klaus, who was biting his lip and staring after where Diego just left. “...Klaus. Klaus!” She snapped her fingers in front of his face to get his attention, and sniffed the air trying to sense what was going on, wrinkling her nose. “God, Klaus, you stink! I thought you were sobering up?”

That caught Klaus’ attention. “Excusez-moi?” He brought his hand up to his chest in offense, not even trying to hide the hurt in his voice or his scent. 

Allison paused when she smelled the bitter upset omega smell coming off of Klaus. “Shit, Klaus. I’m sorry, I didn’t mean it like that…” she trailed off, but he was already pushing past her, back up the stairs. She debated going after him, but knew that she wouldn’t be welcomed, so instead returned to the kitchen where everyone else was. 

When Allison sat down at the kitchen table, Diego lifted his head, looking around for Klaus. He squinted his eyes at her, and took a deep breath in. It was faint, but the scent of Klaus’ distress was there, and suddenly Diego was seeing red. 

“What did you do,” he snapped, then jumped up from his seat to run up the stairs, without waiting for an answer. 

“Diego!” He heard everyone calling after him, but only Ben followed after him, reaching out to stop him. “Diego, give him some time to calm down on his own. He’s probably in the bath right now, and I really don’t think either of you want the first time you see each other like that to be after one of our siblings said something stupid.”

“I don’t know w-what you’re talking about.”

Ben just looked at Diego, unimpressed. “The next few days you guys are probably going to want some privacy, but you’re still going to need some food and water. If you don’t want Luther to be the one bringing it to you, or Allison,” at the mention of the other alpha, Diego let out a growl, which Ben just ignored and continued talking over, “getting her scent all over everything, then I’d suggest you listen to your sweet, doting, wonderfully smart brother who definitely knows best in this situation.” His grip on Diego’s arm was firm, leaving no doubt that Ben wasn’t really giving Diego a choice here. 

Diego sighed, knowing that Ben was right but not wanting to admit it. He clenched his jaw, and flexed his fingers in and out of fists a few times before finally letting out a breath. With a roll of his shoulder, he shrugged out of Ben’s grasp and turned to the stairs heading up. 

“Diego…”

“Just heading to my room, bro,” he held his hands up. “Unless, of course, you’d rather I throw knives around in yours?” 

Once up the stairs, Diego did fully intend on going straight to his room. But right as he got to his bedroom door, another door in the hall opened, and a waft of vanilla and baby powder fell over him. His head shot up to watch as Klaus exited the bathroom, a towel wrapped around himself keeping everything covered. Without even thinking, Diego was suddenly standing in front of Klaus, blocking his path back to his room.

Klaus opened his mouth to say something, and Diego focused on the way his throat moved with every word he said. He wondered what it would feel like.

“...you knothead!” He was pulled back from his thoughts, literally, by Klaus pulling on his hair and yanking him away. “Would you stop scenting me? I just showered and now I smell like alpha again!” 

A rumbling purr escaped Diego at the thought of Klaus smelling like him. He moved forward again to press back into Klaus’ scent gland, but was stopped again by the omega.  
“No,” Klaus bopped Diego on the nose, before sidestepping around him to walk down the hall. “I am going to go lay down for a bit, and enjoy not having alpha smell all over me before I have to. You,” he waved his fingers around a bit, “are going to do whatever alphas do to calm down until you can think with something other than your knot.” With that, Klaus walked in the bedroom and shut the door behind him. 

Diego stood in the hallway for about twenty minutes after that, thoughts of Klaus smelling like him and Klaus wearing nothing but a towel swirling around in his head. It wasn’t until he heard a door slamming shut downstairs that he snapped out of it. It was then that he realized that Klaus wasn’t in his own bedroom, but had instead been in Diego’s room this whole time. 

He ran down the hall, throwing himself against the door before pausing long enough to remember how doorknobs work. He finally managed to get the door opened, and the sight before him had him pausing again.

There, on Diego’s bed, with his ass up in the air, was Klaus. His towel was abandoned on the ground, and Diego’s bed covers had all been shoved down to the foot of the bed, leaving nothing for Klaus to hide behind. Not that Klaus seemed at all interested in hiding. Diego watched, transfixed, as Klaus rolled his hips into the mattress. Pleased omega scent permeated the air, mixing with Diego’s own scent and creating the most heady combination Diego had ever smelled. 

A broken moan escaped Klaus as he noticed Diego in the room, and he lifted his head to turn back and look at the alpha. A flash of black caught Diego’s attention, and he realized that Klaus had been burying his face into it.

“Is that my shirt?” Diego asked, his alpha puffing up in pride at the thought.

Klaus collapsed into the bed, groaning. “Really? You take twenty minutes to follow after me, and when you finally get here, _that’s_ what you notice? Your shirt? I have the dumbest alpha ever.” His complaints were belied by his scent, however, which Diego managed to pick up on right away.

“I thought you didn’t want alpha smell all over you?” Diego took the few steps towards the bed, then kicked his shoes off before climbing on top of the bed, crawling over Klaus. “Not until you had to. Is that it, baby? You had to have your alpha’s smell? 

Underneath him, Klaus started wiggling, rolling over so that he was on his back. “Not just your smell. Want. Want all of you all over me. Please, alpha.” As he talked, Klaus ran his hands over every bit of Diego he could reach, and trying to reach some that he couldn’t. He reached under Diego’s shirt, but was stopped by the harness over it. Klaus started swatting at the offending material, before a laughing Diego reached down to still his hands.

“I don’t know, that’s a pretty big turn around from what you were saying earlier. It’s probably just your heat talking. I can go to one of the old guest rooms, give you some time alone-”

Klaus’ hands reached out and grabbed a hold of Diego’s shirt -the one that he was wearing- and pulled him down to look him in the eyes. “Don’t. You. Dare.”

Diego looked at Klaus, noting that his eyes were still mostly green. He sniffed the air, and while Klaus was definitely aroused, there was still enough of his sweet vanilla scent in the air for him to not be in full heat yet. This was really just Klaus speaking, not his hormones. Diego let out a happy sigh at that, then sat back on his heels, looking down at Klaus. 

“Yeah? You want this?” Diego reached up to undo the straps of his harness, and tossed it to his clothes hamper, knowing the pile of fabric there wouldn’t hurt his knives. He then lifted his shirt up over his head, smirking when he saw Klaus tracking his every movement.

A hitch in his breath told Diego the moment Klaus noticed his nipple ring, and just a moment later, Klaus was reaching a hand up and running his fingers over it. Diego bit his lip to keep from moaning out loud, when Klaus pinched his nipple and gave it a twist. 

If asked, Diego would deny the shout that Klaus shocked out of him at that. Luckily, Klaus was too distracted running hands up and down Diego’s exposed torso, and didn’t seem to care. Happy omega scent filled Diego’s nose, and he had to taste it. He leaned forward to press his mouth against Klaus’ scent gland, but was thwarted by Klaus, who moved his head so Diego’s mouth hit Klaus’ mouth instead. 

As far as first kisses go, it was awful. They adjusted though, especially once Diego caught onto what was happening and actually tried to kiss Klaus back. Their second kiss was much better, as was their third and their fourth. Diego forgot that Klaus needed to breathe, and was really upset when their fifth kiss was cut short, but was quickly calmed down by the smell and taste of his happy omega. 

At some point Diego had started grinding up against Klaus. His pants felt too tight and confining, and as hot as it was to see Klaus’ slick all over them, he needed his pants off and now. With some careful coordination that he really didn’t have, Diego somehow managed to get his pants and underwear off and tossed them on the floor, before turning his full attention back to his omega underneath him. 

“Bout damn time,” Klaus mumbled against his lips. Diego pulled back confused, but already Klaus was moving again, seeking out friction from Diego for relief. 

Diego didn’t even need to scent Klaus this time, there was no doubt in his mind that Klaus’ heat had arrived. He could feel his own rut beginning, no doubt brought on early because of Klaus going into heat. 

In a final moment of clarity, Diego grabbed one of Klaus’ hands and pressed a kiss to the inside of his palm, right over the word hello. He looked up into Klaus’ eyes, and smiled. “I love you.”

Klaus smiled back, moving his hand to the back of Diego’s head and bringing him down to give him another kiss. “I love you, too, you sentimental dork,” he gave Diego a moment to bask in the feelings, “but if you don’t get your dick in me and start knotting me, I am not above kicking you out of your own room and getting myself off alone.” 

It was an empty threat, and they both knew it, so Diego took his time. They had plenty of time over the next few days for quick; Diego wanted their first time to be special. He had a reputation of sentimental dork to uphold, after all. 

Diego pressed another kiss to Klaus’ lips, before trailing along his jawline, down his neck, to his scent gland. He carefully mouthed over it, but pulled back when he felt Klaus tense underneath him. 

“You call the shots. We go as far or as short as you want, I’m not gonna make you do anything you don’t want. Just tell me what you want.” 

Klaus reaches a hand out to grab Diego’s and gave it a squeeze. “Everything. I want everything with you.”

Diego felt his heart jump at that, felt like the whole world was finally all in place. “Yeah?” He asked, and he couldn’t keep the smile off his face. 

“No, I’ve been scenting all over you, called you my alpha, and gone into heat in your room just for the hell of it,” Klaus rolled his eyes. “Yes, Diego! I want everything. I want you. I want you to claim me. I want you to knot me, to fill me, to breed me. Give me your pups, Diego. Give me everything. Diego, _please._ ” 

There were no rules, Diego decided then, that said quick could not be special.

He surged forward again to give Klaus another kiss. He ran his tongue along the roof of Klaus’ mouth, while at the same time one hand ran down along Klaus’ side. Diego sucked on Klaus’ tongue, before breaking away with a wet pop. His hand was on Klaus’ hip now, and he massaged his way back, grabbing a handful of ass and giving it a squeeze. With his left hand, Diego grabbed a hold of Klaus’ leg, stroking his thigh a few times before lifting the leg up to give Diego access. 

Klaus grabbed his leg from Diego and held it up against his chest, and brought the other one up as well to fully display himself to his alpha. A strong scent of baby powder filled Diego’s senses at that, and he gave off his own happy alpha scent. His omega was fertile and ready for him to fill him up. 

Diego looked at the beautiful sight his omega made. Hole on display, all shiny with slick and waiting for Diego. He pressed a finger to the edge of Klaus’ hole, sliding it around the wetness there before plunging in. There was a slight resistance there, but not as much as Diego was expecting. 

“Please, Alpha, I can take it. Just give me your knot, I’m ready,” Klaus was shaking with need, and Diego realized exactly what he meant. Klaus had already prepared himself. 

With a groan of appreciation, Diego pulled his finger out of Klaus, before inserting three at once. Klaus’ muscles clenched around the intrusion, but he was relaxed and ready for more. “You’re so good to me, Omega. So perfect,” Diego pulled his fingers out and gathered up some slick to lube himself up with, then carefully lined the head of his penis up to Klaus’ entrance. “I’m gonna fill you so full. Let everyone see it.” Diego pressed in fully, giving Klaus a moment to adjust to the feeling before pulling out and slamming back in again. 

Klaus gave a loud shout at the fast pace, drawing it out into a moan as Diego adjusted and filled him deeper with every thrust. Diego’s heavy balls were slapping against Klaus’ ass, and his knot was starting to catch on his rim. Klaus hadn’t even had to touch himself yet, and already he could feel his muscles start to tighten, his lower stomach felt like it was about to do a backflip inside of him. He was close. “So close. Come on, Alpha. Wanna feel you come inside of me. Fill me up. Please, Alpha. Want your knot. Want you, Alpha. Please. Please,” he broke off into words that may not have even been English, may not have even been words at all, he didn’t _care_ he just needed to come, needed his alpha to come, needed—

A sharp pain in his neck pulled Klaus out of his thoughts, launching him straight into bliss. He was floating. He was swimming. He was falling, flying, soaring right into his alpha’s arms. 

He came to, with Diego holding him tight in his arms. His stomach was coated in his own cum, and he realized belatedly that Diego was knotting him right now. He reached a hand up to his neck, noting the swelling around his scent gland where Diego had just bit him. Claimed him. 

Klaus reached a hand out to rub across Diego’s scent gland like he so wanted to do earlier. Diego gave a slight twitch at the feeling, and wasn’t that odd to feel from both inside and out? He leaned forward so he could rub his cheek against Diego’s scent gland, letting the minty lime smell permeate his skin. Fresh. His alpha always smelled so fresh. Klaus stuck his tongue out to taste it, surprised when Diego tasted warm despite the cool mint scent. He bit down around the gland, and sucked, leaving his mark as dark as he could get it so it would never have a chance to fade away. 

Diego came with a loud groan at the claim, not having enough in him for a large orgasm since he was already knotting Klaus. His body shook for a few moments as he gave Klaus everything he had at once. As he slowed down, he felt a slight bulge against his stomach, and noted with glee that it was Klaus’ belly distended from how much Diego was filling him with his knot and his seed. 

Klaus noticed where Diego’s attention was and looked down himself, then ran a hand across his belly in appreciation. “‘S nice, this. Stuffed full of you. Perfect, actually,” he leaned onto Diego’s neck, resting his head. “Do you think it took? We’ll have to try a few more times, I’d imagine. _Such_ a hardship, really.” 

A hum was all Klaus got in response, not that he was expecting much. Diego always tended to be quieter during emotional moments, which worked out fine because Klaus was quieter, well, never. 

“We might have to try other positions, too. I read an article once where they swore the best way to have a pup is sideways, with your hip propped up on at least three but no more than five pillows and— what are you doing?” 

Diego pushed Klaus’ head to the side, burying his nose in his neck. “Your scent changed.”

“Well I should hope so! You just mated me, I probably stink of alpha right now!” Diego rolled his eyes, but said nothing, just leaned back in to continue sniffing Klaus. 

After a few more minutes, Diego leaned back, a huge smile on his face. “Your scent changed.” 

Klaus rolled his eyes this time, “yes you said that already, you big knothead.”

Diego shook his head. “No, I mean again. You have another scent on you. Like milk.” Klaus’ head shot up at that, his eyes wide. 

“You don’t mean…”

Diego rubbed a hand across Klaus’ distended belly, where his knot was still inside keeping them together. “I _mean_ , your scent changed.”

Klaus’ smile was even bigger than Diego’s before he pulled his mate in for a breathtaking kiss. When they pulled away, he just started laughing. “Of course it did. You are not going to be one of those awful knotheads who goes around bragging about how they knocked up their omega on the very first try, are you?”

“Why, would I do that?” Diego asked, and he too started laughing. 

Klaus threw his head back and groaned. “Oh my god, you are! Oh what did I just get myself into?”

Diego leaned back into Klaus’ neck, alternating between nuzzling it and pressing kisses to it. “Your scent changed,” he said again quietly, over and over again, as if maybe this time he would be able to actually believe it. 

Klaus ran his fingers through Diego’s hair, letting his words wash over him. His scent changed.

**Author's Note:**

> And as always, huge thanks to everyone at the Kliego discord for your love and support <3


End file.
